In vivo MRI study of the oxidative stress level in the white matter of patients with relapsing-remitting multiple sclerosis / 中华放射学杂志

Objective:To explore the oxidative stress of cerebral white matter lesion (WML) and normal-appearing white matter (NAWM) with in vivo proton exchange rate (k ex) MRI on relapse-remitting multiple sclerosis (RRMS) patients. Methods:Clinical and imaging data of 37 patients (case group) with RRMS patients of Tongji Hospital of Tongji Medical College of Huazhong University of Science and Technology were analyzed retrospectively from November 2018 to November 2021, including 11 males and 26 females aged 18-41 (29±7) years. Another 22 age-matched healthy volunteers (control group) were recruited for the same period, including 4 males and 18 females aged 23-44 years with a median age of 25 (24, 28.25) years. All subjects received conventional MR protocols and chemical exchange saturation transfer imaging. The manifestation of WML on the k ex map and T 1WI images were assessed while the k ex values of WML, NAWM and normal white matter (NWM) of control group were quantitatively evaluated. Student′s t test was used to compare the k ex difference of WML and NAWM in the case group, NAWM in the case group and NWM in the control group, low-signal and isosignal WML in T 1WI. Spearman rank correlation was used to analyze the correlation of the k ex values of WML with patients′ expanded disability status scale (EDSS) score. Results:A total of 272 WML were found in the 37 RRMS patients, and 25.4% (69/272) were T 1-hypointense. The k ex value of WML in the case group [(932±108) s -1] was higher than that of NAWM [(771±26) s -1], and the difference was statistically significant ( t=8.95, P<0.001); the k ex value of NAWM in the case group [(771±26) s -1 ] was higher than that of NWM [(745±26) s -1] in the control group, and the difference was statistically significant ( t=3.96, P<0.001). The k ex value [(1 039±110) s -1] of WML with low signal at T 1WI was higher than that of WML with equal signal [(895±79) s -1], with a statistically significant difference ( t=9.78, P<0.001). Correlation analysis showed that the k ex value of WML in the case group was positively correlated with the EDSS score ( r=0.54, P<0.001). Conclusions:The elevated k ex values of WML and NAWM reflect the cerebral oxidative stress of RRMS patients and are positively correlated to the severity of tissue damage, which suggests the role of oxidative stress in RRMS lesion formation and brain atrophy.

Evaluation of white matter in patients with multiple sclerosis through diffusion tensor magnetic resonance imaging

OBJECTIVE: To study the white matter of patients with multiple sclerosis (MS) with diffusion tensor magnetic resonance (MR) imaging (DTI). METHOD: Forty patients with clinical-laboratorial diagnosis of relapsing-remitting MS and 40 age- and sex-matched controls, who underwent conventional and functional (DTI) MR imaging, were included in the study. The DTI sequences resulted in maps of fractional anisotropy (FA) and regions of interest were placed on the plaques, peri-plaque regions, normal-appearing white matter (NAWM) around the plaques, contralateral normal white matter (CNWM) and normal white matter of the controls (WMC). The FA values were compared and the statistical treatment was performed with the Mann-Whitney U test. RESULTS: The mean FA in plaques was 0.268, in peri-plaque regions 0.365, in NAWM 0.509, in CNWM 0.552 and in WMC 0.573. Statistical significant differences in FA values were observed in plaques, peri-plaque regions and in NAWM around the plaques when compared to the white matter in the control group. There was no significant difference between the FA values of the CNWM of patients with MS and normal white matter of controls. CONCLUSION: Patients with MS show difference in the FA values of the plaques, peri-plaques and NAWM around the plaques when compared to the normal white matter of controls. As a result, DTI may be considered more efficient than conventional MR imaging for the study of patients with MS.

OBJETIVO: Estudar a substância branca de pacientes com esclerose múltipla (EM) através de imagens de ressonância magnética (RM) por tensor de difusão (DTI). MÉTODO: Foram avaliados 40 pacientes com diagnóstico clínico-laboratorial de EM remitente-recorrente e quarenta controles pareados por idade e sexo, os quais foram submetidos à RM convencional e funcional (DTI). As seqüências de DTI resultaram em mapas de anisotropia fracionada (FA) e as regiões de interesse foram posicionadas nas placas, regiões peri-placas, substância branca aparentemente normal (SBAN) ao redor das placas, substância branca normal contra-lateral (SBNC) e substância branca normal do grupo controle (SBC). Os valores de FA foram comparados e a análise estatística foi realizada utilizando o teste Mann-Whitney U. RESULTADOS: A média de FA nas placas foi 0,268, nas regiões peri-placas 0,365, na SBAN 0,509, na SBNC 0,552 e na SBC 0,573. Foram observadas diferenças estatisticamente significativas nos valores de FA nas placas, regiões peri-placas e na SBAN ao redor das placas quando comparados com a SBC. Não houve diferença entre os valores de FA na SBNC dos pacientes com EM e na SBC. CONCLUSÃO: Pacientes com EM demonstram diferença nos valores de FA nas placas, peri-placas e SBAN ao redor das placas quando comparados com a SBC. Assim, o DTI pode ser considerado mais eficiente do que as seqüências de ressonância magnética convencional no estudo dos pacientes com EM.